When will cotton enter China? An introduction to the planting History of Cotton in China

Cotton is one of the most important crops in the world. it is the seed fiber of cotton plants of Malvaceae, which can be made into all kinds of fabrics. at present, the countries with the highest cotton production in the world are China, the United States, India, Brazil, Mexico, Egypt, Pakistan, Turkey, Argentina and Sudan. Let's take a look at when cotton entered China.

When will cotton enter China?

Cotton cultivation first appeared in the Indus Valley civilization of 5-4000BC. The Moors spread the cotton planting method to Spain in about the 9th century, introduced it to England in the 15th century, and then introduced it to the British colonies in North America. At least before 2000, cotton fiber was used as textile raw material in Guangxi, Yunnan and other regions. However, in the Central Plains, at first, people only regarded cotton as an ornamental plant and did not realize its economic value. Due to the poor quality and low yield of African cotton and Asian cotton, China introduced improved varieties of upland cotton from the United States at the end of the Qing Dynasty.

What are the ways in which cotton is introduced into our country?

It is generally believed that cotton spread to the Central Plains from north and south to the Central Plains, and the south road was first Asian cotton from India, and was introduced into Hainan Island and Liangguang through Southeast Asia, at least during the Qin and Han dynasties, and then into Fujian, Guangdong, Sichuan and other regions. The second way was introduced into Yunnan from India through Burma, about during the Qin and Han dynasties. The third way is that African cotton was introduced through West Asia and the Hexi Corridor, about during the Northern and Southern dynasties. North Road is the ancient book "Western regions". During the Song and Yuan dynasties, cotton spread to the Yangtze River and Yellow River basins, and by the 13th century, cotton had spread to the Weihe River Basin in Shaanxi Province.

What varieties of cotton are classified?

1. Coarse cotton: coarse cotton, also known as Asian cotton, originated in India, has become obsolete because of its low yield and short fiber, which is not suitable for machine spinning.

2. Long-staple cotton: long-staple cotton, also known as sea island cotton, is native to South America with long fiber and high strength, which is suitable for spinning high-count yarn with good quality.

3. Fine-staple cotton: fine-staple cotton, also known as upland cotton, originates from Central America, has wide adaptability, high yield, long fiber, good quality and can be spun.

Growth conditions and cultivation techniques of Orange trees

Orange is a kind of fruit of the citrus genus of Rutaceae, which is of origin in China. Thousands of years of cultivation history can not explain the specific location clearly. It has been spread all over Eurasia by Arabs and is still called "Chinese apple" in the Netherlands and Germany. China is one of the important places of origin of orange fruit, rich in resources and a wide variety of fine varieties. Let's take a look at the planting techniques of orange trees.

Planting conditions of orange trees

1. Temperature: the temperature for the growth and development of orange fruit is 12.5-37 ℃, and the temperature for flower bud differentiation in autumn is about 20 ℃ and 10 ℃, respectively. The soil temperature of root growth is about the same as that of aboveground. High temperature was also not conducive to the growth and development of citrus. The fruit and root system stopped growing when the air temperature and soil temperature were higher than 37 ℃.

2. Illumination: orange is a shade-tolerant tree species, but good sunshine is still needed for high quality and high yield. In general, the areas with annual sunshine hours of 1200 to 2200 hours can grow normally. For example, compared with Chongqing citrus producing areas with good sunshine and rich heat, South China has high sugar content, low acid content and high sugar-acid ratio.

3. Humidity: oranges are suitable for planting in tropical and subtropical regions with an annual rainfall of about 1000 mm. The relative water content of the soil is 60% 80%. If the relative water content of the soil is less than 60%, it needs irrigation. Too much Rain Water causes stagnant water in the soil or high groundwater level. it can kill the roots in citrus orchards with poor drainage.

4. Soil: orange can adapt to a wide range of soil, purple soil, red-yellow soil, beach and coastal, ph 4.5-8 can grow, ph 5.5-6.5 is the most suitable. High oxygen content is required for root growth, and the soil with loose texture, good structure, 20.3% organic matter and good drainage is the most suitable.

Planting techniques of orange trees

1. Seedling planting: when the orange seedlings are planted, the roots of the seedlings are trimmed moderately and placed in the center of the planting hole to stretch the roots, straighten the roots, and gently lift the seedlings upward while filling the soil. Pour enough water on the roots, make a 1-meter plate around the seedlings and cover them with bran shells. After planting orange seedlings, we should do a good job of deep hole expansion and ripening soil, forbid planting tall plants such as corn and wheat in the garden, and do a good job of rational intercropping and weeding in orchards.

2. Fertilizer and water management: orange trees should fully meet the needs of blood orange for various nutrient elements, advocate the application of more organic fertilizer, rational application of inorganic fertilizer and formula fertilizer, and guide fertilization according to the results of leaf analysis, orchard soil analysis and blood orange phenology. Soil fertilization is the main method, combined with foliar fertilization. The methods of ring ditch application, furrow application, hole application and soil surface fertilizer application were adopted. The soil is irrigated when it is dry and drained when it is stagnant.

3. Rational fertilization: orange trees should be applied frequently and thinly, mainly nitrogen fertilizer, combined with phosphorus and potassium fertilizer, and fertilized 5-6 times in spring, summer and autumn shoot emergence period. Adult trees apply four times of fertilizer, that is, sprouting fertilizer, fruit protection fertilizer, strong fruit fertilizer, fruit picking fertilizer, sprouting fertilizer 2kg chemical fertilizer, one load of manure water, 1kg fruit protection fertilizer, 1kg phosphate and potassium fertilizer, 1kg fruit fertilizer, 2jin phosphate and potassium fertilizer, 50kg 100kg organic fertilizer and 2jin chemical fertilizer.

4. Pruning techniques: after the elongated branches in the center and the main branches and secondary branches were selected in the young tree stage, they were cut moderately or severely, and the growth balance among the main branches was adjusted by the degree of truncation and the direction of cutting buds. In the result period, we continue to select short-cut treatment of all levels of backbone extension branches, erase summer shoots and promote strong autumn shoots. Measures such as ring cutting, root cutting and water control are adopted to promote flowers for prosperous trees in autumn.

Control of diseases and insect pests in orange trees

1. Foot rot: timely drainage, improve the light transmission and ventilation conditions in the garden, strengthen the control of longicorn beetles and other trunk pests, select disease-resistant rootstocks such as trifoliate orange, orange and orange, and replace disease-resistant rootstocks for susceptible plants.

2. Mites: spring shoot initiation stage, young fruit stage and fruit expansion stage are the main periods for the control of rust lice, and the commonly used pesticides are thiazox, dabalin, acetylid, bromoacarate, dimethomide, etc., and pay attention to protect natural enemies such as long beard mites, blunt mites and lacewings.

3. Scale: commonly used chemicals such as cinothiazin, methamphetamido, matrine + nicotine, Lesbon, oil emulsion, etc., pay attention to improve the ventilation and light transmission conditions in the garden, protect and utilize natural enemies such as Japanese beetle, red-lipped ladybug, lacewings and so on.

4. Aphids: the damage rate of new shoots is up to 25%. It should be sprayed immediately. Commonly used insecticides include chloramidine, dimethoate, butylthiocarb and so on. Attention should be paid to protecting ladybugs, lacewings and aphid wasps, cutting off overwintering eggs and reducing the base number of insect pests.

5. Leaf miner: wipe off the sporadic summer and autumn shoots in time, spray the new shoots to 1: 2 cm, spray once every 7-10 days, 2-3 times in a row. The commonly used agents are avermectin, shamindan, cyhalothrin and so on.

6. Longicorn beetles: adults of longicorn beetles and green orange longicorn beetles are artificially killed at noon on a sunny day, adults of brown longicorn beetles are killed in the evening, eggs, newly hatched larvae and damaged branches are cut off in time, and insecticides such as cotton or cotton yarn are soaked in dimethoate to kill larvae.

7. Flower bud maggots: when budding, fine soil such as diazinon powder and diazinon particles are mixed and sprinkled on the soil surface of the tree plate, once every 7 days, 2-3 times in a row. When the diameter of the bud is 2-3 mm, choose parathion, trichlorfon and other tree crowns.

Is lettuce a genetically modified food?

Lettuce is also known as leaf lettuce, goose lettuce, lettuce, shipping mark lettuce, etc., native to the Euro-Mediterranean coast, domesticated from wild species, the ancient Greeks and Romans were the first to eat, and it has a long history of being introduced into China. There is a lot of cultivation along the southeast coast, especially in the suburbs of big cities and in Guangdong and Guangzhou. Let's take a look at whether lettuce is genetically modified.

Is lettuce genetically modified?

Lettuce is not genetically modified. Lettuce is genetically modified. At present, except for large-scale imports of genetically modified soybeans and corn, other genetically modified vegetables are not common. Although genetically modified tomatoes and other genetically modified vegetables have been approved in China, they have been basically eliminated around the world because of their thick skin and poor taste.

What are the genetically modified foods?

1. Tomatoes: I believe that many people like to eat tomatoes, and it is precisely because most people around the world like this vegetable that scientists have studied tomatoes more deeply, and it is found that the genes of tomatoes are relatively easy to transfer. therefore, the tomatoes eaten today are also slowly becoming genetically modified, and there is even a tendency to start commercial production. It is worth mentioning that although transgenic production of tomato has been approved in China, it has not yet begun large-scale commercial production.

2. Sweet peppers: approved by the Ministry of Agriculture in 1998, genetically modified colored peppers were allowed to be planted commercially, but genetically modified colored peppers do not seem to have received much welcome from the public in our country, and today they basically do not produce genetically modified colored peppers. However, it does not rule out the possibility that some businesses secretly plant genetically modified colored peppers in violation of government regulations.

3. Corn: genetically modified corn has been allowed to be imported into the United States in China, especially on January 7, 2015, an agricultural university developed genetically modified corn varieties in addition to insect-resistant rice, and also won a prize.

4. Rapeseed: we all know that rapeseed can be used to produce oil, so many people who study agriculture will focus on it. Now genetically modified rapeseed is still controversial in governments of various countries. In the final analysis, we are still worried about toxicity and allergy. Although the planting of genetically modified rapeseed has not yet begun to be promoted in our country, genetically modified rapeseed is imported.

5. Soybeans: when we go to buy cooking oil, we often find that some cooking oil will be marked with "genetically modified soybeans". In fact, genetically modified soybeans have begun to enter the Chinese market on a large scale, and they are mainly used for the processing of edible oil. as for whether GM soybeans are sold on the market or not, it is not clear whether they are selling GM soybeans on the market, so if you do not want to eat GM cooking oil, it is recommended to read the product label clearly before buying.

Characteristics of transgenic vegetables

1. Size: without the uneven shape of traditional vegetables, it is generally uniform in size, generally long in shape, bright in color and tender in texture. For example, soybeans should be shaped like animal innards, a little flat, with a waistline, but today's soybeans are all round, like peas, and the yield is very high.

2. Taste: there is no original and authentic taste of traditional vegetables, whether the smell or taste before or after cooking is obviously different from that of traditional vegetables. Traditional corn is generally yellow corn, white corn, slightly sweet, and now popular sweet corn, its sweetness is very high, like adding honey. Sweet corn grain has less wax on the surface, delicate taste, and some are waxy.

3. Season: non-local seasonal vegetables, one of the major characteristics of all kinds of vegetables is that they have strong seasonality and regionality. Some non-local seasonal vegetables are obtained by transplanting cold-tolerant or high-temperature tolerant genes, such as out-of-season winter jujube.

4. Color: different from traditional colors, such as colored cotton, black rice peanuts, purple sweet potatoes.

5. Pests: all vegetables that pests like to patronize are not genetically modified, and vegetables that pests are afraid of, that is, vegetables with no pests, or few pests, are absolutely genetically modified.

6. yield: transgenic vegetables are generally in the first few years, and their yield is much higher than that of traditional vegetables.

7. Seed retention: genetically modified vegetables are generally difficult to keep their own seeds.